Scanning electron microscopes (SEM) are useful research tools which permit microscopic evaluation of samples with much greater resolution and magnification than that possible with conventional light microscopes. However, the procedure necessary to set up and observe numerous samples is cumbersome and requires a great deal of operator time merely to prepare for the microscopic examination.
For instance, conventional electron microscopes are provided with a microscope stage having a planar operative upper surface within which is mounted the sample for observation. In one embodiment, the microscope stage is provided with an aperture into which a sample carrier is placed, with the sample for observation being securely affixed to the upper surface of the carrier. A longitudinal axis through the center line of the aperture is disposed perpendicular to the surface of the microscope stage. Typically, the electron beam from the SEM is focused about this axis which is perpendicular to the microscope stage. In order to observe the specimen in a cross-section, the entire stage must be rotated 90.degree. so that the electron beam will enter the "side" of the specimen as opposed to the "top".
While conventional procedures certainly perform adequately for their intended result, the amount of time needed to replace individual samples on a microscope stage, and the 90.degree. rotation of the stage for cross-sectional views of the specimen, involve an inordinate amount of preparatory time prior to actually making the observation with the SEM. Therefore, Applicants have identified a need for an apparatus which is capable of converting conventional SEM microscope stages from a single-specimen stage to a multiple-specimen stage, in order to permit the microscope operator to insert a number of samples simultaneously into the observation chamber, thereby substantially reducing the setup time necessary for a number of samples. Likewise, Applicants have identified a need for an apparatus to eliminate the need to rotate the SEM microscope stage a full 90.degree. in order to make cross-sectional observations.
Therefore, the apparatus of the present invention enables the SEM operator to insert a plurality of samples for observation simultaneously into the observation chamber.